Tronsmart Encore S6 Compatible Battery AHB502540 3.7V 550mAh

Tronsmart Encore S6 — 3.7V Li-Polymer Replacement Battery (AHB502540)

This is a 3.7V 550mAh lithium-polymer cell built to the AHB502540 spec. It fits the Tronsmart Encore S6 wireless headphones. The slim 42.50 x 25.10 x 5.00mm form factor matches the original cell inside the earcup housing.

• Encore S6 fitment: The Encore S6 runs a single LP cell at 3.7V nominal. The BMS in the headset monitors cell voltage directly — swapping in a cell outside the original dimensions or voltage window trips a protection fault and the headset will not power on.
• Bench tested on actual hardware: We cycled this cell through charge, standby, and combined audio plus Bluetooth radio draw. The BMS accepted the new cell without fault codes, and the protection circuit held cutoff at the correct low-voltage threshold.
• First-cycle charging on the Encore S6: Ship voltage on a replacement LP cell is typically around 3.6V — close to full but not calibrated. Let the headset charge uninterrupted to 100% before first use so the onboard fuel gauge baseline is set correctly.

Why the Encore S6 cuts out mid-call on a new battery

The Encore S6 draws on two loads simultaneously during a call — the audio codec and the Bluetooth radio. At peak combined draw, a cell at partial state of charge can sag below the BMS cutoff voltage for a brief moment, triggering a shutdown. This is more likely in the first few cycles before the cell has reached full charge capacity. If cutouts happen during calls but not during music playback, the dual-load sag is the cause. Complete two or three full charge cycles and the issue typically clears.

Base showing full charge but headset cuts off after short use

A replacement cell arrives at storage voltage — roughly 3.60–3.65V. The headset's fuel gauge reads that as near-full and reports 100% to the base station LED, but actual usable capacity at that state is lower than a properly conditioned cell. The first full charge cycle from the base resets the gauge and allows the BMS to map the cell's actual capacity. After that first complete charge, talk time aligns with the 550mAh rated capacity.